116 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



posterior portion, yet not extending to the posterior margin. The pleural plates 

 are comparatively large, oblong, rounded, thus occupying the whole or at least 

 most of the lateral margin; in the posterior segments they are broader and 

 overlap each other considerably ; their convex ventral side with numerous 

 small tubercles and oblong knots. The three posterior segments on the ventral 

 side Avith an interrupted row of very short fleshy keels ; the other segments 

 are not examined. The legs are robust; the second joint (Fig. Ih and Id} 

 on the outer side with a very high expansion, shaped as an oblique plate, which 

 is about as high as long and somewhat shorter than the length of the joint, on 

 both sides ■with irregular small protuberances ; the other joints normal. In 

 Figure 1 6 is shown the first left leg with the marsupial plate ; this plate shows 

 on the under side a deep transverse furrow and more forward a group of low 

 knots, on the upper side (Fig. 1 c) a kind of transverse keel, the marginal por- 

 tion of which is divided into numerous irregular, small, thin-skinned processes. 

 The basal part of the other four pairs of plates with numerous knots (Fig. 1 a). 

 (The marsupium'of both specimens with eggs.) 



A bdomen. The five anterior segments with very large rounded pleural lamellae, 

 the anterior of which are somewhat transverse, the posterior oblong ; the lamellae 

 cover the main part of one another, a large portion of the dorsal surface of the an- 

 terior segments, and the whole dorsal surface of the posterior ones. In Figure 1 

 the fifth pair of lamell* are lettered a^. The second to the fifth segments on 

 the ventral side each with a transverse row of short fleshy processes or knots, 

 or lamellar keels; the first segment with an interrupted series of low lamellae. 

 The sixth segment (posteriorly behind the attachment of the uropods produced 

 into an oblong, distally rounded and swelled, almost petiolated process. Each 

 pair of pleopods consists of two large rami ; in the anterior pairs these are 

 shorter and rather broadly triangular, backwards they gradually become elon- 

 gate. The uropods biramous, the rami similar to those of the last pleopods ; 

 in Figure 1 a the visible distal part of the rami on the left side of the figure 

 are marked with 6, on the right side with 6^. The main part, or almost the 

 whole, of both surfaces of the pleural lamellae and of the pleopods and uropods is 

 set with very low and irregular minute keels and more rounded protuberances, 

 which are most developed on the anterior pleopods. 



Size. The largest specimen — which has been taken as type for all the fig- 

 ures — is 14.2 mm. long to the end of the abdomen, 17.3 mm. long to the apex 

 of the longest ramus of the uropods, and 10.9 mm. broad. The other specimen 

 measures 15.6 mm. to the end of the uropods. 



b. Male. 



One specimen (Plate IV. Fig. 2 b) is symmetrical and undoubtedly normal ; 

 the other specimen (Fig. 2 c) is anomalous, not symmetrical, and somewhat 

 misshapen, — especially the abdomen is conspicuously different. In the fol- 

 lowing the normal specimen is described, with some remarks concerning the 

 other. 



